Mazda Trucks 1972-1986 Repair Guide

Idle Speed


See Figure 1

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Fig. Fig. 1: View of the idle adjustment points on the diesel engine: accelerator cable locknut (1), accelerator cable adjusting nut (2), idle adjusting bolt locknut (3), idle adjusting bolt (4)


See Figure 2

You'll need a tachometer that works with diesel engines.

  1. Make sure that the throttle cable deflection, at the pump, is 1.0mm-3.0mm. Adjust it with the adjusting nut, if it is not.
  3. Loosen the locknut on the idle speed adjusting bolt. Turn the bolt to the right to increase the idle; to the left to decrease it.
  5. Race the engine two or three times and let it return to idle. Check the idle speed and readjust if necessary. Idle speed should be 700 rpm.

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Fig. Fig. 2: Tune-Up Specifications: Diesel Engines